Photographic material



United States Patent 3,359,106 PHOTOGRAPHIC MATERIAL Jozef Frans Willems and Albert Lucien Poot, Wilrijk- Antwerp, and Paul Dsir Van Pee, Edegem, Belgium, assignors to Gevaert Photo-Producten N.V., Mortsel- 5 Antwerp, Belgium, 21 company of Belgium No Drawing. Filed Mar. 30, 1964, Ser. No. 355,912 Claims priority, applicationsBelgium, Mar. 29, 1963,

42, 1 4 Claims. (Cl. 96-52) ABSTRACT OF THE DISCLOSURE The present invention relates to photographic printing material containing compounds which prevent the image obtained from being bronzed by hot glazing or mechanical drying at elevated temperature, and to photographic baths wherein such compounds are dissolved.

The images obtained in light-sensitive silver halide emulsion layers of a photographic printing material often undergo changes during hot glazing or during mechanical drying at elevated temperature, since during these treatments a loss of density arises which is also called plumming or bronzing of the sliver image.

It is known to incorporate small amounts of chemical compounds into light-sensitive material containing a silver halide emulsion printing layer, or into processing baths for such material in order to prevent this loss of density.

In most cases, these compounds only partially prevent brorizing and moreover exert a rather desensitizing action 0 upon the light-sensitive material when incorporated into the latter.

Now has been found that when incorporating into a light-sensitive material having at least one silver halide emulsion printing layer or when dissolving in at least 45 one of the processing baths for such material at least one 6-thioxo-5,6-dihydrobenzimidazo 1,2-c]quinazoline, practically no loss of density of the developed silver containing image occurs by hot glazing or drying at elevated temperature.

These benzimidazo[1,2-c]quinazolines may be substituted e.g. by an alkyl radical, an alkoxy radical, a halogen atom, an amino group or an acetylamino group. They may also be applied in the form of their tautomers or salts of these tautomers.

Some particularly appropriate compounds for being used according to the invention are:

their tautomers and salts of these tautomers.

These benzimidazo[l,2-c]quinazolines can be prepared as described by A. Foot, J. Willems and F. Huygebaert, Bull. Soc. Chim. Belg, 72 (1963) 365.

3,359,106 Patented Dec. 19, 1967 When the 6 thioxo 5,6-dihyd-robenzimidazo[1,2-c] quinazolines are incorporated into one of the component layers of the light-sensitive material, they do not only prevent the silver-containing image from losing density on hot glazing or drying at increased temperature as described before, but they also reduce the fog without influencing the sensitivity and gradation to some noteworthy extent. The 6-oxo-5,6-dihydrobenzimidazo[1,2-c] quinazolines, their tauitomers and the salts of these tautomers also show this property. Therefore all these 5,6-dihydrobenzimidazo[l,2-c]quinazolines may also be applied to high-sensitive negative material, often in combination with other stabilizers. When incorporating the benzimidazo[l,2-c]quinazolines of use according to the invention into the photographic printing material, they are generally incorporated into the light-sensitive silver halide emulsion printing layer itself. They can be added to the printing silver halide emulsion at any moment during its preparation, but preferably after chemical ripening or just before coating. This addition occurs in general from a solution of the compound in an appropriate solvent such as water, alcohol, dimethylformamide and so on. Instead of incorporating the compounds into the photographic printing layer, they can also be incorporated into an additional water-permeable layer such as a gelatin covering layer or an intermediate layer. Evidently, mixtures of different benzimidazo[1,2-c]quinazolines may be used as well.

The total concentration of benzimidazo[1,2-c]quinazolines in the light-sensitive printing material may vary within wide limits, but is preferably chosen in such a way that per sq. m. of light-sensitive material from some mg. to approximately 500 mg. of this compound or compounds are present.

Light-sensitive material according to the present invention may comprise any printing halogen silver emulsion layer such as for instance a gelatino silver chloride emulsion layer, a gelatino silver chlorobromide emulsion layer, a gelatino silver chloroiodide emulsion layer, a gelatino silver bromide emulsion layer, a gelatino silver bromoiodide emulsion layer and a gelatino silver chlorobromoiodide emulsion layer. The silver halide emulsion may contain all known additives, such as anti-fogging agents, stabilizers, hardening agents, plasticizers and dispersing agents. Further, it may be sensitized chemically as well as spectrally. It may be chemically sensitized by effecting the ripening in the presence of small amounts of sulphur containing compounds, for instance allyl isothiocyanate, allyl thiourea, sodium thiosulphate and so on. The lightsensitive printing emulsions can also be sensitized by means of reducing agents for instance the tin compounds described in the Belgian patent specifications 493,464 and 568,687, the iminoaminomethane sulphinic acid compounds described in the British patent specification 78 9,- 823 or by means of small amounts of noble metal compounds such as gold compounds, platinum compounds, palladium compounds, iridinum compounds, ruthenium compounds and rhodium compounds. Furthermore, it is also possible to sensitize the emulsions with polyoxyalkylene derivatives, for instance polyoxyethylene of a molecular weight ranging between 1000 and 20,000 or condensation products of alkylene oxides with aliphatic alcohols, glycols, cyclic dehydration products of heXitols, alkylsubstituted phenols, aliphatic carboxylic acids, aliphatic amines, aliphatic diamines and aliphatic amides. The condensation products have a molecular weight of at least 700, preferably of more than 1000. For attaining special eifects these sensitizers, of course, can be applied in combination as described in the Belgian patent specificacation 537,278 and in the British patent specification 727,982.

Instead of incorporating the compounds to be used according to the invention into the photographic printing material, they can be dissolved in one of the processing baths such as the developing bath, the fixing bath, an additional hardening bath, and a bath which contains surfaceactive compounds and which is used as a last treating bath before hot glazing or before drying, at elevated temperature of the image-containing material. In most cases, the 6 thioxo 5,6 dihydrobenzimidazo[1,2 c]quinazolines are dissolved in the bath in the form of their alkali salts in concentrations which can vary within very wide limits preferably, however, between approximately 50 mg. and approximately 1000 mg./ liter. When the the photographic printing material is led through such a bath, it absorbs a certain amount of the benzimidazo[l,2-c]quinazoline into its water-permeable layers, which assures as well the retaining of the density of the silver-containing image during hot glazing or drying at high temperature as does the presence of the anti-bronzing agent in the light-sensitive material from its preparation on.

The following examples illustrate the invention.

EXAMPLE 1 Material 1 Material 1 is prepared as follows:

A gelatino silver chloride emulsion, prepared with a proportion of silver nitrate to gelatin of 1 to 4 (28.3 g./ 113.2 g. per kg. of emulsion) is applied to a baryta-coated paper support in such a way that after drying an amount of silver halide, equivalent to 1.5 g. of silver nitrate is present per sq. m. of light-sensitive material. This lightsensitive layer is coated with a thin gelatin covering layer which is hardened afterwards.

Material 2a Material 2a is prepared as Material 1 with the difference, however, that per kg. of light-sensitive emulsion, ready for coating, 0.3 g. of 6-thioxo-5,6-dihydrobenzirnidazo [l,2-c]quinazoline is added from a 1% solution in dimethyl formamide.

Material 2b Material 2b is prepared as Material 1 with the difference, however, that per kg. of light-sensitive emulsion, ready for coating, 1 g. of 6-thioxo-5,6-dihydrobenzimidazo[.1,2-c]quinazoline is added from a 1% solution in dimethyl forma-mide.

Material 3a Material 3a is prepared as Material 1 with the difference, however, that per kg. of light-sensitive emulsion, ready for coating, 0.3 g. of 6-thioxo-9-methyl-5,6-dihydrobenzimidazo[l,2-c]quinazoline is added from a 1% solution in dimethyl formamide.

Material 3b Material 3b is prepared asMaterial 1 with the diiference, however, that per kg. of light-sensitive emulsion, ready for coating 1g. of 6-thioxo-9-methyl-5,6-dihydrobenzimidazo [1,2-c]quinazoline is added from a 1% solution in dimethyl formamide.

A strip of each of these five materials is exposed for some minutes and developed for five minutes at 20 C. in a bath of the following composition:

Water cc 800 p-Monomethyl aminophenol sulphate g 1.5 Anhydrous sodium sulphite g 50 Hydroquinone g 6 Anhydrous sodium carbonate g 32 Potassium bromide g- 2 Water up to 1000 ccs.

4 The five material strips are rinsed for a moment and then fixed for five minutes at room temperature in the following composition:

Water cc 800 Anhydrous sodium thiosulphate g 120 Potassium meta-bisulphite g 25 Water up to 1000 ccs.

Next, the strips are rinsed for 30 minutes and dipped for some seconds in the following preservation solution:

2 sulpho 2' [(3,4 dichlorophenyl)ureylene] 4,4

dichlorodiphenylether g 2 Water cc Acetone ..cc 20 The five material strips are finally pressed for 6 minutes with their light-sensitive side to a polished plate of 80 C.

Then, the density of the various material strips is measured with a Macbeth densitometer before as well as after hot glazing. The following results are attained:

From these results it clearly appears that a material according to the present invention loses very little or no density at all by hot glazing.

EXAMPLE 2 Material 1 Material 2 is prepared as Material 1 with the difference, however, that per kg. of light-sensitive emulsion, ready for coating, 0.3 g. of 6 thioxo 9 methyl 5,6 dihydrobenzimidazo[1,2-c]quinazoline is added from a 1% solution in dimethyl formamide.

Material 3 Material 3 is prepared as Material 1 with the difference, however, that per kg. of light-sensitive emulsion, ready for coating, 0.3 g. of 6-thioxo-9-methexy-5,6-dihydrobenzimidazo[1,2-c]quinazoline is added from a 1% solution in dimethyl formamide.

A strip of each of these three materials is treated in the same way as the material strips of Example 1. The following results are attained:

Density before Density alter hot glazing hot glazing Material 1 (comparison material). 1. 98 1. 50 Material 2 2. 04 l. 98 Material 3 1. 97 1. 94

From these results the same conclusions can be drawn as from the results of Example 1.

EXAMPLE 3 Material 1 Material 1 is prepared as Material 1 of Example 2.

M aferial 2 Material 2 is prepared as Material 1 with the difference, however, that per kg. of light-sensitive emulsion, ready for methyl-5,-dihydrobenzimidazo[1,2-c]quinazoline is incorporated from a 1% solution in dimethyl formamide in such a Way that 20 mg. are present per sq. m. of lightsensitive material.

' Material 3 iaterial 3 is prepared as Material 1 with the difference, however, that into the gelatin covering layer 6-thio:=:o9- methoxy-S,6-dihydrobenzimidazo[1,2-c1quinazoline is incorporated from a 1% solution in dimethyl formarnide in such a way that 20 mg. are present per sq. m. of lightsensitive material.

A strip of each of these materials is treated in the same way as the material strips of Example 1. The following results are attained:

Density before Density after hot glazing hot glazing Material 1 (comparison material) 1. 96 1. 50 Material 2 a 2. 03 1. 96 Material 3- 1. 96 1. 93

From these results the same conclusions can be drawn as from the results of Example 1.

EXAMPLE 4 Material 1 Material 2 Material 2 is prepared as Material 1 With the difference, however, that per kg. of light-sensitive emulsion, ready for coating, 0.3 g. of 6-thioXo-5,6-dihydrobenzimidazo [1,2-c]quinazoline is added from a 1% solution in dimethyl formamide.

Material 3 Material 3 is prepared as Material 1 with the difference, however, that per kg. of light-sensitive emulsion, ready for coating, 0.3 g. of 6-thioxo-9-methyl-5,6-dihydrobenzimidazo[l,2-c]quinazoline is added from a 1% solution in dimethyl formamide.

Material 4 Material 4 is prepared as Material 1 with the ditference, however, that per kg. of light-sensitive emulsion, ready for coating, 0.3 g. of 6-thioxo-9-methoXy-5,6-dihydrobenzimidazo [1,2-c]quinazoline is added from a 1% solution in dimethyl formamide.

A strip of these materials is treated in the same way as the material strips of Example 1 and the following results are attained:

From these results the same conclusions can be drawn as from those of Example 1.

EXAMPLE 5 Four strips of a material, composed as the comparison material from Example 4, are treated as the material strips of Example 1, with the difference, however, that (1) for the processing of the second material strip 0.5 g. of 6- thioXo-5,6-dihydrobenzirnidazo[ 1,2-c1quinazoline is dis- 20 solved in the developing bath (per liter), (2) for the processing of the third material strip 0.5 g. of the above compound is dissolved in the fixing composition (per liter) and (3) for the processing of the fourth material a hardening bath (4t)% aqueous formaldehyde solution) containing 5 per liter 0.5 g. of the above compound wherein the ma terial is treated for 10 minutes, is included as last processing bath.

The following results are obtained:

Density before Density after hot glazing hot glazing Material 1 (comparison material) 1. 78 1. 34 Material 2 2.02 2.05 Material 3.- 1.88 1. 94 35 Material 4 1. 74 1. 78

From the above results appears clearly that the antibronzing agents of use according to the present invention are also very active when incorporated into one of the processing baths.

We claim:

1. Photographic material comprising a support and at least one light-sensitive silver halide emulsion printing layer incorporating a 6 thioxo 5,6 dihydrobenzimidazo [1,2-c] quinazoline.

2. Photographic material comprising a support, at least one light-sensitive silver halide emulsion printing layer and at least one additional Water-permeable layer incorporating a 6 thioxo-S,6-dihydrobenzimidazo[1,2-c] quinazoline.

3. Photographic material comprising a support, at least one light-sensitive silver halide emulsion printing layer incorporating a 6 thioxo 5,6 dihydrobenzimidazo[1,2-c] quinazoline, and at least one additional water-permeable layer incorporating a 6-thioxo-5,6-dihydrobenzimidazo [1,2-c] quinazoline.

4. Photographic processing bath incorporating a 6- thioxod,6-dihydrobenzimidazo[ 1,2-c1quinazoline.

References Cited OTHER REFERENCES Poot et =al.: Bull. Soc. Chim. Belg, vol. 72, pp. 365- 373 (1963).

NORMAN G. TORCHIN, Primary Examiner.

I. TRAVIS BROWN, Examiner. R. E. MARTIN, Assistant Examiner. 

1. PHOTOGRAPHIC MATERIAL COMPRISING A SUPPORT AND AT LEAST ONE LIGHT-SENSITIVE SILVER HALIDE EMULSION PRINTING LAYER INCORPORATING A 6-THIOXO-5,6-DIHYDROBENZIMIDAZO (1,2-C) QUINAZOLINE. 